Device for connecting the abutting ends of concrete slabs



une 7 1927. J c. E. BOWERS DEVICE-FOR CONNECTING THE ABUTTING ENDS OF CONCRETE SLABS Filed Oct. 11, 1926 I N VEN TOR. {kl/Z62. i 072973 A TTORNE Y.

I Patented June 7. 1927.

UNHTE CLAUDE E. BOWERS, OF LOS ANGELES, CALIFORNIA inn-we DEVICE FOR connncrmo THE ABUTTING ENDS or cononn'rn SLABS.

Application filedOctober 11, 1926. Serial No. 140,739.

This invention relates to a device for connecting the abutting ends of concrete slabs of roadways, which will serve to compensate for the contraction and expansion thereof, as well as to hold the abutting slabs or blocks in alinement, thereby assuring an even surface at the joints.

A main object of the invention is to provide a device which will effectually prevent a vertical or lateral shifting movement of adjacent concrete slabs of a roadway, but will readily permit of a longitudinal movement of the connected slabs. p

The above and other objects of my invention will be'more fully disclosed in the following specifications, reference being had to the accompanying drawings forming a part thereof,in which:

Fig. 1- is a partial plan view of a concrete roadway with the connecting devices in position.

-Fig. 2 is a side elevation of the contract- -ible metal sleeve.

sleeve showing the overlap.

Fig. 4 is a longitudinal section through In an embodiment of the present invention the joints are adapted to 'be' formed transversely across the concrete roadway at suitable intervals as shown in Fig. 1 of the drawings, and are constructed in the followmg manner. p

When slab 5 of the roadway 6 has'been poured a number of round steelbars' or dowels 7 approximately three-fourths 7 ofan inch in diameter and about twenty-four (24) inches long are inserted in the edge 8 of the slab midway between the top and th'e bottom surfaces, about half their lengths projectingbeyond the edge as clearly shown 1n the various views of the drawings.

' The exposed ends of these rods are then greased or oiled to prevent corrosion or.

sticking, and the contractible metal tubes 9 are then apphed to the exposed ends.

Fig. 3 is an enlarged cross section of the Tubes 9 that form sockets for the projecting ends of the embedded rods constitute one ;of the important features of the-invention and are preferably formed from sheet steel of No. 28 gage about twelve and three-quarters (12%) inches,'their longitudinally extendingedges 10, 11 overlapping each other about one half an inchin order to permit of a diametrical contraction of the sleeves when pressure is applied thereto,- the pressure being exerted thereagainst by the mass of concrete when the same is poured therearound in the formation of the adjacent slab, see 'Figs. 2, 7, and 8. One end of the tube or sleeve is prov'ided'wit-h a die formed-metal cap 12, and its ep site endis provided with a metal ring 13, t e cap and ring maintaining the tube in its initial shape, the cap also serving to prevent an entrance of wet con- "crete to the interior of the tube or sleeve during the concrete pouring operation. As the cap 12, and ring 13 are liable to become accidentally detached during handling a small drop of solder 14 may be applied to each to temporarily hold them in position, as shown in Fig. 2.

In order to provide suflicient space within the sleeves to accommodate the movement rods with respect to the sleeves when an expansion of the slabs occur, stops 15 are formed by indenting the surface of the sleeves a distance from the capped end about equal to the normal width of the joints 16, the ends of the rods on an expansion of the slabs forcing the stops outwardly and pernillttlng their passage into the space beyond -t iem.

As initially formed the diameter of the tubes 9-are slightly larger than the diam eters of the rods of dowels 7 in order that they may be readily inserted thereon, the pressure of the wet concrete being sufficient to contract the sleeves transversely into a tight glove fit with the rods or dowels .after the .completion of the concrete pouring operation. As the tubes are formed of thin gage metal it will be apparent that when they become disintegrated by corrosion that the sockets formed in the'concrete by the tubes will only be slightly larger than the diameter of the rods, and as a result there. will be little if any of vertical or lateral movement of the slabs. v

After the slabs have been poured and set,

bituminous mastic or other elastic material the joints between the same are filled with a 1 17 in order to prevent leakage of fluid between or under the slabs.

By the above recited construction it will be perfectly obvious that the metal rods or dowels 7 will efi'ectually prevent the slabs or blocks from shifting with respect to one another in either a vertical or lateral direction, thus assuring an even surface and straight edges to the roadway, and that the slabs may expand and contract freely in a longitudinal direction by reason of the rods and sockets. Further as the devices are formed of comparatively inexpensive materials it will be apparent that their cost will be adequately compensated by the benefits derived.

What I claim is: j

1. In a device 'for connecting the slab units of a concrete roadway, a plurality of rods adapted for embedment in an edge of one of the concrete slab units, a portion of the rods extending beyond the edge, and a contractible metal sleeve for each of said rods, said sleeves being embedded in the abutting edge of the adjacent concrete unit.

2. In a device for connecting the slab units of a concrete roadway, a plurality of metal rods adaptedforembedment in an edge of one of the concrete slab units, a

portion of the rods projecting beyond the edge, and diametrically contractible metal sleeves disposed upon the free ends of the projecting rods, said sleeves adapted for embedment in the abutting edge of the adjacent concrete slab unit.

3. The combination with a pair of abutting concrete road slab units, a plurality of metal rods partially embedded in an ed e of one of the slab units, and a transverse y contractible metal sleeve mounted on each of said metal rods, the said, sleeves being embedded in the abutting edge of the adjacent slab unit.

4. A device for preventing vertical and lateral movement of concrete road slab units, comprising a plurality of metal rods adapted for partial embedment in an edge of one of said units, and a longitudinally split sleeve mounted on the free end of each metal rod, the concrete of the abutting edge of the adjacent unit surrounding the sleeve and compressing the same into a tight sliding .engagement with the metal rods.

5. A device of the class described comprising a plurality of metal rods, a longitudinally split metal sleeve for each of said rods, the rods and sleeves adapted to be embedded in the abutting edges of concrete road slab units, whereby to prevent vertical and lateral movement'of the slabs when the same contract or expand.

6. A device of the class described com- 

